1. Field of the Invention
The present invention relates generally to an insole of a shoe, and more particularly to a method of making a ventilative insole.
2. Description of the Related Art
A conventional ventilative insole is classified into a pore-formed molding type and a mold molding type according to the method of forming the pores of the insole. The first type is that the piece of insole is processed to form the pores after it is molded and the second type is that the insole is molded with the pores by foaming molding method.
In the process of foaming of the foaming material, there is a skin layer molded on a surface of the insole for reinforcement. The advantage of the insole of the first type is that the distribution of pores is designated by manufacturer but it will damage the skin layer while the insole is formed with the pores. Such insole has no skin layer at portions adjacent to the pores that the pores will easy to be damaged after a long time of use. The insole of the second type has a skin layer both on the surface of the insole and the sidewall of the pores. There must be an average distribution of pores on the insole to prevent the insole from break while it is shrunk after foaming.